class Counter1{
    private  int count =0;

    public void add(){
        synchronized (this){
            count++;

        }

    }
    public int getCount(){
        return count;
    }
}
public class demo21 {
    public static void main(String[] args) throws InterruptedException {
        Counter1 counter1= new Counter1();
        Thread t1 =new Thread(()->{
            for (int i = 0; i < 50000; i++) {
                counter1.add();
            }
        });
        Thread t2 =new Thread(()->{
            for (int i = 0; i < 50000; i++) {
                counter1.add();
            }
        });
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println("count="+counter1.getCount());

    }
}
